Sheet separating



Oct. 11, 1966 D w. SLEEPER ETAL 3,278,180

SHEET SEPARATING Filed April 15, 1964 5 Sheets-Sheet 1 FIG. I

INVENTORS.

NORMAN W. TAYLOR 8| DONALD W- SLEEPER ATTORNEY Oct. 11, 1966 D. w.SLEEPER ETAL SHEET SEPARATING Filed April 15, 1964 5 Sheets-Sheet 2INVENTORS.

TAYLO R 8| NORMAN W. F DONALD W. SLEEPER ATTORNEY 1966 o. w. SLEEPERETAL 3,278,180

SHEET SEPARATING Filed April 15, 1964 III-I... a

5 Sheets-Sheet 5 FIG. 6

I. "a. I.

I r: INVENTORS.

NORMAN W. TAYLOR a 464 BYDONALD W. SLEEPER MK/QOZ- ATTORNEY UnitedStates Patent 3,278,180 SHEET SEPARATING Donald W. Sleeper, Euclid, andNorman W. Taylor, Cleveland, Ohio, assignors to Addressograph MultigraphCorporation, Cleveland, Ohio, a corporation of Delaware Filed Apr. 15,1964, Ser. No. 360,011 Claims. (Cl. 271-19) This invention relates tosheet handling and especially to the separation of sheets, one-by-one,from the top of a stack of sheets and forwarding them for being workedupon, for example by a printing machine.

Heretofore in medium cost sheet handling equipment devices, sometimesreferred to as corner separators, have been employed which provide frontstops for the corners of a stack of sheets and from whic the top sheetcan escape when moved forward by a sheet moving element. While theseprior devices can sometimes be made to operate fairly effectively withthe paper of certain types, they have little flexibility and willnormally handle only very usual types and sizes of paper. When widevariations from the normal are encountered, the corner separatorsusually must be changed, or in some cases cannot be made to work at all.

It is an object of the invention, therefore, to provide a cornerseparator arrangement in which the corner separator elements have anovel configuration calculated to provide wide latitude in the types ofpaper that can be handled without changing separators, and which willreliably separate sheets one-by-one from the stack over a wide range ofpaper weights, paper surfaces, and sheet sizes.

It is another object of the invention to provide an improved cornerseparator arrangement capable of cooperating with an adjustable pressuresetting such that the corner separators can be made to positivelydepress the corners of the sheets to a certain predetermined degree,which degree is capable of adjustment in order to further extend therange of conditions under which sheets may be reliably separated and fedforward.

It is a further object of the invention to provide corner separatorswhich combine positive retention features for the lower sheets whilegenerating a positive release action for the top sheet.

The provision of corner separators capable of the foregoing flexibilityand wide range of effectiveness, but not adding significantly to thecost of equipment, is also an object of the invention.

Other objects, features and advantages will appear hereinafter as thedescription proceeds.

In the drawing:

FIG. 1 is a fragmentary longitudinal section of a printing machineemploying the corner separators of the present invention;

FIG. 2 is a front elevation of a corner separator element looking fromthe direction of the paper pile;

FIG. 3 is a right side elevation of the device of FIG. 2 to a largerscale;

FIG. 4 is a fragmentary top plan of the corner sepa rator of FIG. 2;

FIG. 5 is a partial back elevation of the upper portion of the cornerseparator element of FIG. 3, showing the relationship of the sheetsthereto during operation and prior to a starting motion;

FIGS. 6 to 9 are schematic sectional views to a large scale, lookingfrom the same direction as FIG. 2, and illustrating the position of thesheet in various stages of the separating action.

Referring to the drawing, FIG. 1 shows one form of printing machine inwhich the corner separators of the present invention find application.The machine comprises parallel side plates, one of which is indicated at3,278,180 Patented Oct. 11, 1966 11, between which are mounted printingelements, for example the printing'cylinder 30 and the platen cylinder40. Means including feed rollers 101 and 102 are provided for presentinga sheet of paper to the bight of cylinders'30 and 40 at the propermoment to be printed, and a sheet separating and starting device 300 isprovided for separating the top sheet from a stack of sheets S on apaper table 401, and moving the same forward into the control of thefeed rollers 101, 102. The table carries members 403 and 405 verticallyslidable in guide slots 407 and 409 on the machine frame. Means (notshown) is preferably provided for automatically bringing the table to aheight such that the top sheet of the stack S will be presented at apredetermined level. Various ways of arranging this are known, forexample that illustrated in the US. Patent to Curtis, No. 2,165,232, sothat no additional description or showing is necessary.

The sheet starting device 300 comprises an oscillating lever 303, thelower tip of which appears in the drawing, and which is driven in timewith the rotation of printing cylinder 30. To the lever 303 is pivotallyconnected a rack 365, which meshes with a pinion which drives a shaft353 via an over-running clutch 361 so that shaft 353 turn in onedirection only.

Drivingly associated with the shaft 353 are one or more rollers such asthat indicated at 351 which have friction contact with the top sheet ofthe stack S and which are rotated in the direction of the arrow to movethe top sheet to the right. Means such as adjustable tension springs 369may be employed to provide the proper degree of friction between theroller and the sheet.

The action of separating the top sheet from the pile and doing soreliably for various kinds and weights of paper is achieved according tothe present invention in a novel and inexpensive Way involving thecooperation of the roller on rollers 351 with means at each of the twocorners of the paper pile nearest the feed rollers 101, 102. These meansare referred to as corner separators and act partly as front stop meansfor the pile, and also as means to release the sheet from such frontstopped condition in response to forward urging of the sheet. One ofthese corner separators is shown in FIGS. 2 to 9 of the drawing where itis indicated generally by the reference character 450. While in eachview only that member 450 which is on the left hand side of the machineis illustrated, it will be readily understood that there will usuallyalso be such a member on the right hand side of the machine, whichmember is identical except for being of opposite hand. Each of thecorner separators 450 is made of two sheet metal plates. The main plate451 has a flange 453 turned at right angles thereto along its outeredge, and at the upper end at the corner formed by said flange is acarefully formed cap configuration 455. This is characterized bv fiveimportant features:

(1) The forwardmost portion of the cap joins the plate 451 in a slopingcrease 456, and is slightly flattened adjacent the crease 456 asindicated at 457 in FIG. 3 to form a narrow sloping ledge. The crease456 is not sharp but rather has a noticeable interior radius.

(2) The ledge 457 and the crease 456 slope downwardly towards the flange453 so that all three surfaces meet at a corner 459 which is at a lowerelevation than the inner end of the crease 456. There is also a slightcrease 460 in the flange running rearwardly from this corner on a slightupward slope.

(3) The innermost edge surface of the cap, indicated at 461, follows agenerally helical path starting at the rearmost point 463 and windingforwardly, first upwardly and then downwardly, in a generally inwarddirection to merge with the rest of plate 451 at the inner end of crease456.

(4) The surfaces of the cap portion, and especially the edge 461 havehad their corners rounded and are very smooth, and have been treated toresist wear, as by chrome plating.

(5) The length-to-Width proportions of the cap element in plan view arealso significant, and should be held very close to 8:3. For averagepaper feeding the length dimension L in FIG. 4 should be substantially/2 inch, and the width dimension W about inch.

The front wall of the separator just below the cap 455 slopes downwardlyaway from the flange 453 as indicated at 464 making an angle of a fewdegrees from the vertical, and the edges of this slope are alsosmoothed.

The rest of the corner separator is made up of an auxiliary plate 465attached to plate 451 as by spot welding. The central horizontal sectionis bent to form a guide loop 467. At the outside end, portions of theplate 465 are extended beyond the flange 453 and bent to provide fingers469 which form between themselves and the flange 453 a guide groove 471for a purpose which will presently be explained.

The corner separators are mounted upon a rectangular bar 473 which runsacross the machine at the inner end of the feed table 401, the bar 473passing slidably through the loops 467, whereby the corner separatorscan be laterally positioned to suit the width of the sheets being fed.This positioning is automatically effected by adjustable side guides 475which can be moved laterally and set in various positions on the feedtable in any well known manner. The forward edge of each side guide 475is designed to extend into the guide groove 471 of its corner separator450 so as to move the same with it whenever a sheet width adjustment ismade.

The corner separators 450 are also capable of simultaneous verticaladjustment. The bar 473 (FIG. 1) has extensions which are slidablymounted in slots 477 in the frame, one of which is shown in this view.At each end of the bar 473 there is a vertical operating member 479secured to the bar and formed at its lower end with a follower cage 481which embraces a cam 483. The two cams 483, one of which is shown inFIG. 1, are drivingly secured to a long shaft 485 which is rotatable inthe side plates and carries at one end a suitable operating knob (notshown) by which both ends of the bar 473 can be simultaneously raised orlowered. A suitable friction detent such as a spring washer may beprovided to maintain the shaft 485 in any desired adjusted position.

The operation of this vertical adjustment contributes an additionaldegree of flexibility. It is known that the most effective way tocontrol accurate separation by corner separators is by placing lightpressure on the corners of the sheets and causing the sheet to extractitself from this light frictioued retention. Such pressure is frequentlyprovided by springs or weights applied to the separators but it has nowbeen determined that it is much more effective to fix the cornerseparators at a predetermined level and then rely upon the automaticraising of table 401 to apply the proper degree of pressure to thecorners by raising the top of the pile to standard height. The reasonfor this appears to be that the degree of pressure, to provide optimumfunctioning, should be adjusted to take care of different weights ofpaper and different surface characteristics. This arrangement rendersthe corner pressure delicately and infinitely adjustable in a simplemanner without interchanging parts, and in such manner that the operatorcan readily change it during running to select the optimum pressuresetting for existing conditions.

It will be understood that when a pile is in place on the table 401, andthe table raising mechanism has brought the table to standard height,the setting of the corner separators will cause a slight downwardcompression on the pile corners, the degree of which depends upon thelevel at which bar 473 has been set. This condition is illustrated inFIG. 5 which represents what would be seen by an observer at theposition of the feed roll 101 looking toward the left in FIG. 1. Thecorners of the upper sheet, therefore, are lightly trapped anddownwardly deflected by the frictional action of the ledge portion 457before the sheet starting action begins.

When the rollers 351 begin to turn, the sheet assumes a slightfore-and-aft upward buckle, extending across the front margin of thesheet, since the front edge is stopped against the plates 451 of cornerseparators 450. Very shortly, however, the buckling lateral edges of thesheet, by riding up the helical edges 461 of the caps 455 are cammedlaterally towards each other and hence exert a stress which snaps thesheet corners inwardly towards each other until they are finally free ofthe light frictional pressure applied by ledges 457. Once the sheetcorners are free, the sheet, still tending to straighten laterally,forces its edges first against the upper parts of edges 464, and thenagainst the forward part of the curved edges 461. Since these slopeoutwardly and upwardly away from the center line in this zone, the sheetcams itself upward and then ultimately feeds forward riding the tops ofthe caps 455 to proceed towards the feed rollers 101, 102, providing anoutstandingly reliable single sheet release action not heretoforeachievable with separating equipment of this general nature and costrange.

The release action of the corner separators 450 can be adjusted aspreviously indicated, by lowering or raising the same with respect tothe standard pile height as determined by the setting of the automaticraising mechanism for the table 401. This adjustment not only controlsthe amount of depression of the sheet corners, but also determines theprecise width of front stop encountered due to the slope of edges 464.The specific shape of caps 455 heretofore described in cooperation withthe slope 464 has provided an arrangement which reacts well forseparating papers of many types, and the provision of corner pressureadjustment has extended this range even farther. With the arrangementshown and described it is found possible to feed reliably sheets varyingin surface character from bond to parchment to calendered surfaces andpossibly even certain coated stocks. Sheet sizes from 3" x 5" to 11" X17" have been accurately and reliably separated. Even envelopes areproperly fed. One of the main features is the provision of reliableretention for the sheets below the one being separated, which thepressure of sloping ledge 457 against the depressed corners nicelyprovides still without impairing release of the top sheet. Thesequential action of releasing a sheet is shown in detail in FIGS. 6 to9, taken in order. These are views looking towards the feed rollers 101,102 and wherein the sheets of the sheet stack S are sectioned by a planepassing through the points of contact with the separators. This sequenceof positions actually occurs very rapidly so that the corners of thesheet appear to snap out from under the corner separators. However, inspite of this the action is extremely smooth and controlled due to theparticular shape of the separators themselves.

While in the foregoing description the use of two corner separators hasbeen described and is normally preferable for the best control, it willbe understood that a single corner separator will prove operable in manycases and the invention is not limited in this regard.

From the foregoing, it can be seen that we have provided an improvedconfiguration for a corner separator which makes it possible for theoperator of a machine such as a printing machine to successfully feedsheets of many times without making structural changes in the cornerseparator structure, and so that simple machine adjustments which can beeffected while the machine is running are all that are required in orderto provide a very wide latitude in the type and size of sheet beinghandled.

While the preferred embodiments of the invention have been described andillustrated, it is to be understood that these are capable of variationand modification. Accordingly, the aim of the appended claims is tocover all such variations and modifications as may fall within the truespirit of the invention.

What is claimed is:

1. A corner separator comprising a plate adapted to lie against the leadend of a stack of sheets adjacent to a corner thereof; and a cap at theupper end of said plate having an inner edge which proceeds from theside edge of the top sheet of the stack along a helix upwardly, inwardlyand downwardly to a point near the leading edge of the sheet.

2. A corner separator comprising a plate adapted to lie against the leadend of a stack of sheets adjacent a corner thereof; and a cap having aninner edge which proceeds from the side edge of the top sheet along ahelix upwardly, inwardly and downwardly to a point near the leading edgeof the sheet, and a narrow ledge, forwardly and outwardly sloping, inintimate contact with a narrow margin of the sheet adjacent its leadingedge.

3. A corner separator comprising:

a front wall adapted to lie against the lead end of a stack of sheetsadjacent a corner thereof, said wall having an exterior edge positionedto parallel the corner of a stack of sheets;

a cap;

a front wall junction with said cap extending upwardly at an obtuseangle along said front wall junction and extending to said exterioredge, said cap sloping upwardly in all areas from said junction;

said cap having a cam edge beginning at said front wall junction adistance from said exterior edge and sloping away from said front wallat an acute angle in relationship to the lateral direction of said frontwall, and at a slightly ascending angle with respect to the verticalplane of the front wall, and thereafter progressing upwardly andcontinuing in said acute angle relationship with respect to said frontwall to an apex and then downwardly to a terminus about on a planenormal to said front at said wall exterior edge.

4. A corner separator comprising:

a front wall adapted to lie against the lead end of a stack of sheetsadjacent a corner thereof;

a side Wall, said side wall and front wall meeting along a verticallyextending fold;

a cap;

a front Wall junction with said cap extending upwardly along said frontwall at an obtuse angle with respect to said fold;

a side wall junction with said cap extending upwardly along said sidewall at an obtuse angle with respect to said fold;

said front and side wall junctions meeting at said vertically extendingfold to form a converging threesurface corner of said front and sidew-allls with said cap, said cap sloping upwardly in all areas from saidthree-surface corner;

said cap having a cam edge beginning at said front wall junction atdistance from said corner and sloping upwardly from said front wall at aslightly ascending attitude, and thereafter progressing upwardly at agreater angle and toward said side wall to an apex and then downwardlyto a terminus at the plane of said side wall;

whereby, the cap is embodied in two major portions, the one portionadjacent the front wall causing the corner of a top sheet in a stack toturn down, but prohibiting a full buckle at the corner, therebyconditioning the sheet to buckle laterally, and the other portion beingan inwardly curving cam to press the sheet laterally and create a frontend buckle.

5. Corner separator apparatus comprising:

guide means for establishing a work position for the sheets of avertical stack of paper sheets in superposed relationship;

means for advancing the top sheet of a positioned stack in a directionalong the plane of said top sheet;

an abutment surface adjacent the front position of a corner of a stackin said guide means for restraining sheets in the top area of a stackagainst free advance movement;

a cap ledge extending from said abutment surface over said work positionin a canted attitude sloping upwardly in a direction toward the oppositecorner position for restraining the top sheet against a free curvebuckle in the direction of sheet advance and permitting a bucklelaterally;

a turnboard cam rearwardly of said abutment surface continuing from saidcap ledge over said work position, said cam and cap ledge having acommon edge surface extending in a generally angularly direction acrossthe corner of said work position.

References Cited by the Examiner UNITED STATES PATENTS 3,110,489 11/1963Zahradnik 271-22 3,210,071 10/1965 Rogers 27122X M. HENSON WOOD, JR.,Primary Examiner. I. N. ERLICH, Assistant Examiner.

1. A CORNER SEPARATOR COMPRISING A PLATE ADAPTED TO LIE AGAINST THE LEADEND OF A STACK OF SHEETS ADJACENT TO A CORNER THEREOF; AND A CAP AT THEUPPER END OF SAID PLATE HAVING AN INNER EDGE WHICH PROCEEDS FROM THESIDE EDGE OF THE TOP SHEET OF THE STACK ALONG A HELIX UPWARDLY, INWARDLYAND DOWNWARDLY TO A POINT NEAR THE LEADING EDGE OF THE SHEET.